1. Field of the Invention
This invention relates to the field of flow restrictors for controlling and limiting fluid flow and in particular to a flow restrictor used in a showerhead assembly.
2. Background Art
In fluid transport systems, it is often desired to include a means of controlling or limiting the flow of fluid from an outlet. For example, in showerhead assemblies, it may be desired to control the rate of water flow from the showerhead by means of a flow restrictor. In water sensitive areas, in particular California and other western states, legislatively mandated flow rates may be imposed as a conservation measure. In such instances, it is mandatory to provide a flow restrictor that is nonremovable, so as not to defeat the ultimate goal of conservation of water.
In the prior art, flow restriction is typically achieved by providing a small orifice somewhere in the water delivery system to limit the maximum flow rate of the entire system to that of the orifice itself. However, there are several disadvantages associated with such a scheme.
Of primary concern is contaminant clogging of the orifice. Commercial water supply systems include a variety of particles and contaminants of various sizes Contaminates of a size greater than the orifice would accumulate at the orifice, eventualy blocking it or so severely restricting the flow as to render the showerhead assembly inoperable.
One prior art method of dealing with the problem of contaminants is the use of a screened filter upstream of the restricting orifice. However, the screen can also become clogged with contaminants and must be cleaned frequently to maintain operation. In addition, the screen is an additional article of manufacture, adding to the cost and complexity of the showerhead assembly.
Another method of contaminant management is the use of a plurality of holes to avoid single point failure. However, each of a plurality of holes must be smaller than a single hole orifice in order to provide the same flow limiting capabilities. As a result, small contaminant particles will be blocked by the holes resulting in blockage.
Finally, the above methods all introduce high velocity vibration and accompanying noise levels to operation of the showerhead assembly. Such noise is undesireable and to be avoided.
Therefore, it is an object of the present invention to provide a flow restrictor for use in a fluid delivery system such as a showerhead assembly which will be free from clogging by contaminant particles.
It is another object of the present invention to provide a flow restrictor for fluid delivery systems and showerhead assemblies in which high velocity noises associated with its operation are reduced or eliminated.
It is a further object of the present invention to provide a flow restrictor for use in a fluid delivery system for a showerhead assembly which may be operated for long periods of time without user maintenance.
It is still another object of the present invention to provide a flow restrictor for use with a fluid delivery system or showerhead assembly which may be produced economically and with the minimum of complexity.